Lubricating composition



, acardic acid and 10% cardol.

Patented Nov. 20,1945

- UNITED 2,389,513 LUnnIoA'riNG COMPOSITION Lebbeus C. Kemp, Jr.,' Scarsdale, N'. Y., asslgnor to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Application November 10, 1942.

Serial N- 465167 7 13 Claims. (Cl. 252-465) The present invention relates to lubricating compositions possessing extreme pressure properties, and particularly to an additive composition which, when incorporated in lubricating oils and greases, imparts extreme pressure properties thereto.

The additive ingredients of the present invention are prepared from the phenolic compositions present in or derived from the oils extracted from the Anacardium genus of the Anacardiaceae family. The oils included within this classification are such oils as cashew nut shell'oil, marking nut shell oil, Japanese lac, etc., whose chemical composition depends upon the particular method of extraction used. It is the consensus of the authorities on these extracted oils that the chemical composition of the naturally-occurring oils consists primarily of various types of arcmatic derivatives such as anacardic acid (CzzHazOs) cardol (C32H52O4), cardanol (CzoHszO), anacardol (CisHaoO), urushiol (Gaol-13002), etc. These aromatic derivatives are very unstable and in the presence of heat form decomposition products or oil-insoluble polymerization products.

Representative of these naturally-occurring oils is cashew nut shell oil which, when obtained by solvent extraction, consists primarily of 90% an- The anacardic acid portion of this solvent-extracted oil, which is described as a salicylic acidhomolog, decomposes at slightly elevated temperatures with the evolution of carbon dioxide to yield cardonal, which is a phenol containing an unsaturated alkyl radical (6141121) in the meta .position. This decomposition is particularly noticed in the cashew nut Y shell oil obtained by a thermal extraction process which contains only about 16% anacardic acid, with the balance made up of a major proportion of cardanol and a minor proportion of cardol.

It has been found that an ester of phosphoric acid in which the ester radical is derived from an unsaturated alkyl phenol obtained from an oil extracted from the Anacardium genus of the Anacardiaceae family, is possessed of exceptional extreme pressure properties when incorporated in a hydrocarbon oil. In accordance herewith a high pressure lubricant, such as gear lubricants, gear oils, cutting oils, pressure greases, lubricating oils for internal combustion engines, etc., is obtained by the addition of small quantities of these phosphoric acid esters to a suitable lubrieating oil or grease base- These extreme pressure additives are prepared from the oil-soluble unsaturated alkyl phenolspresent in or derived from the extracted oils and may take the form of mono-, di-, or tri-substituted esters of phosphoric acid, with preference given to the tri-substituted ester. Examples of the unsaturated alkyl phenols suitable for the preparation of these additives are cardanol,. anacardol, urushiol, and the oil-soluble phenolic components which have not been isolated and which may be present in admixture with other phenols in the distillate and distillate residues of the extracted oils. These unsaturated alkyl phenols are relatively unstable and susceptible to polymerization and condensation reactions in the presence of acids and elevated temperatures.

This instability may be overcome by rendering the unsaturated constituents less reactive by such methods as partial hydrogenation or substitution reactions. These stabilization methods are not critical to the preparation of the phosphoric acid esters, but may be used where polymerization conditions are encountered and when additional improving properties are desired, as, for example, improvement of the extreme pressure properties by halogenation or sulfurization of the unsaturated constituents.

The phosphoric acid esters may be incorporated in a hydrocarbon oil, and particularly in mineral lubricating oils and greases in amounts ranging between 0.1-l0.0% by weight, dependin upon the type of hydrocarbon 011 base and the degree of extreme pressure properties desired. The particular range of proportions as applied to some of the lubricating oils and grease bases may be outlined as follows:

In the preparation of the additive compositions of the present invention any of the known methods for preparing phosphoric acid estersare contemplated. The particular method chosen depends upon the conditions of reaction and the stability of the phenolic composition. It is preferred, when reacting the unsaturated alkyl phenols, to select a method of preparation which is carried out at low temperatures and which either does not yield acidic by-products or in which the acidic by-products are removed fgrom the reaction zone. These conditions of reaction, however, may be modified if the starting material has been stabilized by partial hydrogenation or substitution.

The following example of the preparation of tri-cardanyl phosphate is given as an illustration of one of the methods of preparing these phosphoric acid esters:

Example 500 grams of cardanol, obtained by distillation of thermally-extracted cashew nut shell oil, and 137 grams of pyridine were dissolved in 700 cc. of toluene and cooled to 5 C. by means of an icesalt mixture.

- 88.8 grams of POCla were added dropwise to the solution while stirring. After one-half of the P001: was added the ice-salt bath was removed and the second half of the P001: was added at room temperature. The reaction flask warmed up to about 50 C. during the addition of the second half of the F001;. The reaction mixture was then stirred for two hours and allowed to stand overnight. The next day it was warmed to 60 C. and held at that temperature for four hours while stirring. Thereafter, the reaction product was cooled and the tricardanyl phosphate filtered and stripped of the solvent.

The effectiveness of the phosphoric acid esters of the present invention as extreme pressure agents when incorporated in lubricating oils has been demonstrated by tests conducted on an Almen testing machine. For these tests varying amounts of tricardanyl phosphate were incor-.

porated in a solvent-refined, dewaxed, Mid-Continent lubricating oil of an S. A. E. 30 grade. The results obtained (indicated as the pounds of pressure required for seizure) are as follows:

Pounds Reference oil 1 5 Reference oil+ 1.0% tricardanyl phosphate 2 22 3. A lubricant comprising a hydrocarbon oil containing 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from cashew nut shell oil.

4. A lubricant comprising a mineral lubricating oil containing 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from cashew nut shell oil.

5. A high pressure lubricant comprising lubricating oils and greases having incorporated therein 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from oils extracted from the Anacardium genus of the Anacardiaceae family.

6. A lubricant comprising a mineral lubricating oil containing 0.110.0% by weight, based on the finished lubricant, of a tri-substituted organic ester of phosphoric acid, said organic ester being derived from along chain unsaturated alkyl phenol present in or derived from oils extracted from the Anacardium genus of the Anacardiaceae family.

7. ,A lubricant comprising a mineral lubricating oil containing 0.110.0% by weight, based on the finished lubricant, of a tri-substituted organic ester of phosphoric acid, said organic ester I being derivedv from a long chain unsaturated Reference oil+2.5% tricardanyl phosphate 2 23 Represents average of three test runs.

Represents average of six test runs.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A lubricant comprising a hydrocarbon oil containing 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from oils extracted from the Anacardium genus of the Anacardiacea family,

2. A lubricant comprising a mineral lubricating oil containing 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from oils extracted from the Anacardium genus or the Anacardiaceae family.

alkyl phenol present in or derived from cashew nut shell oil.

8. A high pressure lubricant comprising oils and greases having incorporated therein 0.1- 10.0% by weight, based on the finished lubricant of an organic ester of phosphoric, acid, said organic ester being derived from a long chain unsaturated alkyl phenol present in or derived from cashew nut shell oil.

9. A lubricant comprising a hydrocarbon oil containing 0.110.0% by weight, based on the finished lubricant, of an organic ester of phosphoric acid, said organic ester being derived from a partially hydrogenated long chain unsaturated alkyl phenol present in or derived from cashew nut shell oil.

10. A lubricant comprising a hydrocarbon oil and 0.110.0% by weight, based on the finished v lubricant, of tricardanyl phosphate.

11. A lubricant comprising a mineral lubricating oil and 0.110.0% by weight, based on the finished lubricant, of tricardanyl phosphate.

12. A high pressure lubricant comprising lubricating oils and greases having incorporated therein 0.110.0% by weight of tricardanyl phosphate.

13. A lubricant comprising a mineral lubricating oil and 0.110.0% by weight, based on the finished lubricant, of the reaction product of POCI3 and cardanol,

LEBBEUS C. KEMP, Ja. 

